HARARE, Zimbabwe — Zimbabwe's main opposition party claimed an early lead in national elections but the government did not release results Sunday and sent riot police into the streets, raising fears of a violent dispute.

No results were officially announced by evening, 24 hours after the end of voting. Independent election monitors said riot police and other security forces were deployed in densely populated suburbs of the capital, Harare, a traditional base of opposition to President Robert Mugabe, 84.

Discontent with Mugabe has grown nationwide as inflation has soared beyond 100,000 percent and the election was seen as the toughest challenge to his 28-year rule.

U.S. Secretary of State Condoleezza Rice fueled that fire of discontent, saying while in the Middle East that the Mugabe regime "is a disgrace to the people of Zimbabwe and a disgrace to southern Africa and to the continent of Africa as whole.”

In past elections, officials have released results as they were tallied by district, often within hours of the close of voting.

"Clearly the delay is fueling speculation that something might be going on," said Noel Kututwa of the Zimbabwe Elections Support Network, an independent monitoring organization. He said tallies in some districts had been completed Saturday night.

Vote tallies were posted overnight on the doors of individual polling stations. Campaign workers for the opposition Movement for Democratic Change reported the results to party officials by cell-phone text message.

MDC officials said party head Morgan Tsvangirai was leading the presidential race with 67 percent of votes, based on returns from 35 percent of polling stations nationwide.

Party Secretary-General Tendai Biti said it had won nearly all parliamentary seats in Harare and Zimbabwe's second city, Bulawayo, also opposition strongholds. He said they had also taken areas where Mugabe has swept votes in the past — the districts of Mashonaland West and Masvingo and the northeastern town of Bindura, home to a feared ruling party youth brigade known for beating up opposition supporters.

The outcome of the race was impossible to predict without results from other rural areas, where three-quarters of Zimbabwe's population live and Mugabe garners most of his support.

Open hands vs. clenched fistsStill, MDC supporters celebrated in the streets, giving each other the open-handed wave that is the opposition party's symbol. Mugabe's is a clenched fist.

"The people's victory is on course," Biti said Saturday night. "We have absolutely no doubt that we are winning this election."

But Hapisson Mate, a 23-year-old first-time voter, was worried: "Why are we not getting the results? It's very clear to me Mugabe wants to steal this election."

Police had tried to persuade the opposition leaders not to announce results, arguing it was illegal for anyone other than the Electoral Commission to do so. But the opposition party's lawyers said the information already was public.

"I have no doubt that the large part if not all results are known. It is frustrating," Marwick Khumalo, head of the Pan-African Parliament observers, told South African Broadcasting Corp. TV.

Khumalo said the delay has the potential of "upsetting a very peaceful electoral process".

Officials cite complicated electionZimbabwe's Electoral Commission chairman, Judge George Chiweshe, said the vote tally was taking time because Zimbabweans, for the first time, were voting for president, the two houses of Parliament and local councilors, so four ballots have to be counted for each voter instead of one.

"This has been a more complicated election. We will be releasing the results as soon as we can," he said.

Chiweshe was hustled, running, through the lobby by security agents, pursued by people shouting, "We want results!"

Election observers who visited the commission's headquarters early Sunday said it appeared to have only a skeleton staff and seemed in no rush.

"The regime is at a loss and it is taking its time deliberately," Biti charged, saying they were concerned by the delay.

If no presidential candidate wins 50 percent plus one vote, there will be a runoff.

Voting was generally peaceful, with Zimbabweans standing in lines for hours, but African observers questioned thousands of names on the official roll.

Mugabe dismissed rigging charges.

"I cannot sleep with a clear conscience if there is any cheating," he said Saturday after voting and promising to respect results. "If you lose an election and are rejected by the people, it is time to leave politics."

The independent Zimbabwe Election Support Network's monitors reported a heavy police presence at polling stations, ostensibly to help illiterate voters and allowed under a belated presidential decree that breaks an agreement signed with the opposition. The opposition said it was intimidation.

Biti and his party have said their agents and supporters were barred from polling stations in several districts, ballot boxes were stuffed, and election rolls were inflated with dead or fictitious people.